Alert archive / California / Wind Advisories in 2024
Wind Advisory 26, NWS Eureka, CA
NWS Eureka, CA issued this wind advisory at Nov 20, 2024, 2:23 PM PST for Humboldt County, Mendocino County, California. It took effect at Nov 20, 2024, 10:00 PM PST. It was in force for 30 hr.
The area
The counties it named.
The facts
- Issued
- Nov 20, 2024, 2:23 PM PST (22:23 UTC)
- In effect from
- Nov 20, 2024, 10:00 PM PST
- Expired
- Nov 22, 2024, 4:00 AM PST
- In force
- 30 hr
- Issued by
- NWS Eureka, CA
Counties Humboldt County, CA, Mendocino County, CA
The radar
The Eureka (Bunker Hill) radar (KBHX), 71 km from the middle of the area, began a volume at 22:23 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Medford/Jackson, OR (KMFR), launched 12:00Z, 10.4 hours before the alert went out and 266 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 772 m above ground
- 0-6 km bulk shear
- 101 kt
- 0-1 km storm-relative helicity
- 237 m²/s²
- 0-3 km storm-relative helicity
- 513 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
002 WWUS76 KEKA 202223 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 223 PM PST Wed Nov 20 2024 CAZ109-210630- /O.NEW.KEKA.WI.Y.0026.241121T0600Z-241122T1200Z/ Mendocino Coast- Including Fort Bragg, Point Arena, and Rockport 223 PM PST Wed Nov 20 2024 ...WIND ADVISORY IN EFFECT FROM 10 PM THIS EVENING TO 4 AM PST FRIDAY... * WHAT...South winds 20 to 30 mph with gusts up to 50 mph expected. * WHERE...Mendocino Coast. * WHEN...From 10 PM this evening to 4 AM PST Friday. * IMPACTS...Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. Secure outdoor objects. && $$ CAZ114-115-210600- /O.CON.KEKA.WI.Y.0025.000000T0000Z-241121T0600Z/ Northern Lake-Southern Lake- Including Gravelly Valley Airport and Knobcone Camp 223 PM PST Wed Nov 20 2024 ...WIND ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING ELEVATIONS ABOVE 1500 FT... * WHAT...South winds 15 to 25 mph with gusts up to 45 mph for elevations above 1500 ft. * WHERE...Lake County. Strongest winds expected in the Mayacmas Mountains, particularly around Cobb. * WHEN...Until 10 PM PST this evening. * IMPACTS...Wind gusts will be particularly strong along windward ridges. There is an increased risk of tree branches and other debris on roadways. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. Secure outdoor objects. && $$ CAZ101>106-210630- /O.NEW.KEKA.HW.A.0006.241122T0000Z-241122T1200Z/ Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast- Southwestern Humboldt-Northern Humboldt Interior-Southern Humboldt Interior- Including Dinsmore, Kneeland, Ft Dick, Hoopa, Pepperwood, Fernbridge, McKinleyville, Honeydew, Arcata, Crescent City, Weitchpec, Petrolia, Fortuna, Alderpoint, Shively, Shelter Cove, Orleans, Whitethorn, Benbow, Trinidad, Eureka, Willow Creek, Bull Creek, Ferndale, Klamath, Fieldbrook, Bridgeville, Ettersburg, Smith River, Briceland, Garberville, Samoa, and Gasquet 223 PM PST Wed Nov 20 2024 ...HIGH WIND WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT... * WHAT...South winds 25 to 35 mph with gusts up to 65 mph possible. * WHERE...Del Norte County, and Humboldt County. * WHEN...From Thursday afternoon through late Thursday night. * IMPACTS...Damaging winds could blow down trees and power lines. Widespread power outages are possible. Travel could be difficult, especially for high profile vehicles. Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and warnings for updates. Fasten loose objects or shelter objects in a safe location prior to the onset of winds. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka DB
6 follow-up statements
467 WWUS76 KEKA 210551 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 951 PM PST Wed Nov 20 2024 CAZ114-115-210700- /O.EXP.KEKA.WI.Y.0025.000000T0000Z-241121T0600Z/ Northern Lake-Southern Lake- Including Gravelly Valley Airport and Knobcone Camp 951 PM PST Wed Nov 20 2024 ...WIND ADVISORY WILL EXPIRE AT 10 PM PST THIS EVENING... The winds will continue to diminish tonight, although it may take some time over the higher terrain. Additional strong winds are possible Thursday night. $$ CAZ109-211400- /O.CON.KEKA.WI.Y.0026.241121T0600Z-241122T1200Z/ Mendocino Coast- Including Point Arena, Fort Bragg, and Rockport 951 PM PST Wed Nov 20 2024 ...WIND ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... * WHAT...South winds 20 to 30 mph with gusts up to 50 mph expected. * WHERE...Mendocino Coast. * WHEN...Until 4 AM PST Friday. * IMPACTS...Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. Secure outdoor objects. && $$ CAZ101>106-211400- /O.CON.KEKA.HW.A.0006.241122T0000Z-241122T1200Z/ Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast- Southwestern Humboldt-Northern Humboldt Interior-Southern Humboldt Interior- Including Crescent City, Benbow, Fernbridge, Ferndale, Ettersburg, Hoopa, Pepperwood, Ft Dick, Petrolia, Weitchpec, Orleans, Gasquet, Whitethorn, Alderpoint, Briceland, Shelter Cove, Fieldbrook, Smith River, Klamath, Samoa, Garberville, Fortuna, Arcata, Bridgeville, Kneeland, Shively, Eureka, Dinsmore, Trinidad, Bull Creek, McKinleyville, Honeydew, and Willow Creek 951 PM PST Wed Nov 20 2024 ...HIGH WIND WATCH REMAINS IN EFFECT FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT... * WHAT...South winds 25 to 35 mph with gusts up to 65 mph possible. * WHERE...Del Norte County, and Humboldt County. * WHEN...From Thursday afternoon through late Thursday night. * IMPACTS...Damaging winds could blow down trees and power lines. Widespread power outages are possible. Travel could be difficult, especially for high profile vehicles. Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and warnings for updates. Fasten loose objects or shelter objects in a safe location prior to the onset of winds. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka MKK
712 WWUS76 KEKA 211345 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 545 AM PST Thu Nov 21 2024 CAZ109-212145- /O.CON.KEKA.WI.Y.0026.000000T0000Z-241122T1200Z/ Mendocino Coast- Including Point Arena, Fort Bragg, and Rockport 545 AM PST Thu Nov 21 2024 ...WIND ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... * WHAT...South winds 20 to 30 mph with gusts up to 55 mph. * WHERE...Mendocino Coast. * WHEN...Until 4 AM PST Friday. * IMPACTS...Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. Secure outdoor objects. && $$ CAZ101>106-212145- /O.CON.KEKA.HW.A.0006.241122T0000Z-241122T1200Z/ Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast- Southwestern Humboldt-Northern Humboldt Interior-Southern Humboldt Interior- Including Smith River, Dinsmore, Honeydew, Benbow, Alderpoint, Pepperwood, Bridgeville, Samoa, Eureka, Klamath, Ettersburg, Weitchpec, Fernbridge, Ferndale, Fortuna, Hoopa, Bull Creek, Gasquet, Fieldbrook, Shelter Cove, Ft Dick, Briceland, Orleans, Kneeland, Shively, Whitethorn, Arcata, Willow Creek, Trinidad, Garberville, Crescent City, McKinleyville, and Petrolia 545 AM PST Thu Nov 21 2024 ...HIGH WIND WATCH REMAINS IN EFFECT FROM 4 PM PST THIS AFTERNOON THROUGH LATE TONIGHT... * WHAT...South winds 25 to 35 mph with gusts up to 65 mph possible. * WHERE...Del Norte County, and Humboldt County. * WHEN...From 4 PM PST this afternoon through late tonight. * IMPACTS...Damaging winds could blow down trees and power lines. Widespread power outages are possible. Travel could be difficult, especially for high profile vehicles. Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts and warnings for updates. Fasten loose objects or shelter objects in a safe location prior to the onset of winds. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka ZVS
888 WWUS76 KEKA 211502 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 702 AM PST Thu Nov 21 2024 CAZ101-102-212315- /O.UPG.KEKA.HW.A.0006.241122T0000Z-241122T1200Z/ /O.NEW.KEKA.HW.W.0007.241122T0000Z-241122T1200Z/ Coastal Del Norte-Del Norte Interior- Including Smith River, Gasquet, Ft Dick, Crescent City, and Klamath 702 AM PST Thu Nov 21 2024 ...HIGH WIND WARNING IN EFFECT FROM 4 PM THIS AFTERNOON TO 4 AM PST FRIDAY... * WHAT...South winds 20 to 30 mph with gusts up to 65 mph expected. * WHERE...Del Norte County. * WHEN...From 4 PM this afternoon to 4 AM PST Friday. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain in the lower levels of your home during the windstorm, and avoid windows. Watch for falling debris and tree limbs. Use caution if you must drive. && $$ CAZ103>106-212315- /O.UPG.KEKA.HW.A.0006.241122T0000Z-241122T1200Z/ /O.EXB.KEKA.WI.Y.0026.241122T0000Z-241122T1200Z/ Northern Humboldt Coast-Southwestern Humboldt-Northern Humboldt Interior-Southern Humboldt Interior- Including Dinsmore, Honeydew, Benbow, Alderpoint, Pepperwood, Bridgeville, Samoa, Eureka, Ettersburg, Weitchpec, Fernbridge, Ferndale, Fortuna, Hoopa, Bull Creek, Fieldbrook, Shelter Cove, Briceland, Orleans, Kneeland, Shively, Whitethorn, Arcata, Willow Creek, Trinidad, Garberville, McKinleyville, and Petrolia 702 AM PST Thu Nov 21 2024 ...WIND ADVISORY IN EFFECT FROM 4 PM THIS AFTERNOON TO 4 AM PST FRIDAY... * WHAT...South winds 20 to 30 mph with gusts up to 60 mph expected. Up to 70 mph over the more prominent ridges. * WHERE...Humboldt County. * WHEN...From 4 PM this afternoon to 4 AM PST Friday. * IMPACTS...Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. && $$ CAZ109-212315- /O.CON.KEKA.WI.Y.0026.000000T0000Z-241122T1200Z/ Mendocino Coast- Including Point Arena, Fort Bragg, and Rockport 702 AM PST Thu Nov 21 2024 ...WIND ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... * WHAT...South winds 20 to 30 mph with gusts up to 55 mph. * WHERE...Mendocino Coast. * WHEN...Until 4 AM PST Friday. * IMPACTS...Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. Secure outdoor objects. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka ZVS
832 WWUS76 KEKA 212109 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 109 PM PST Thu Nov 21 2024 CAZ103>106-220515- /O.UPG.KEKA.WI.Y.0026.241122T0000Z-241122T1200Z/ /O.EXB.KEKA.HW.W.0007.241122T0500Z-241122T1200Z/ Northern Humboldt Coast-Southwestern Humboldt-Northern Humboldt Interior-Southern Humboldt Interior- Including Shelter Cove, Fieldbrook, Ferndale, Fernbridge, Trinidad, and Fortuna 109 PM PST Thu Nov 21 2024 ...HIGH WIND WARNING IN EFFECT FROM 9 PM THIS EVENING TO 4 AM PST FRIDAY... * WHAT...South wind gusts up to 60 mph along the coast and up to 75 mph over the interior mountains. * WHERE...Humboldt County. * WHEN...From 9 PM this evening to 4 AM PST Friday. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain in the lower levels of your home during the windstorm, and avoid windows. Watch for falling debris and tree limbs. Use caution if you must drive. && $$ CAZ101-102-220515- /O.EXT.KEKA.HW.W.0007.241122T0500Z-241122T1200Z/ Coastal Del Norte-Del Norte Interior- 109 PM PST Thu Nov 21 2024 ...HIGH WIND WARNING NOW IN EFFECT FROM 9 PM THIS EVENING TO 4 AM PST FRIDAY... * WHAT...South wind gusts up to 60 mph along the coast and up to 75 mph over the interior mountains. * WHERE...Del Norte County. * WHEN...From 9 PM this evening to 4 AM PST Friday. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain in the lower levels of your home during the windstorm, and avoid windows. Watch for falling debris and tree limbs. Use caution if you must drive. && $$ CAZ109-220515- /O.CON.KEKA.WI.Y.0026.000000T0000Z-241122T1200Z/ Mendocino Coast- Including Point Arena, Fort Bragg, and Rockport 109 PM PST Thu Nov 21 2024 ...WIND ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... * WHAT...South wind gusts up to 50 mph. * WHERE...Mendocino Coast. * WHEN...Until 4 AM PST Friday. * IMPACTS...Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. Secure outdoor objects. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka DB
151 WWUS76 KEKA 220515 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 915 PM PST Thu Nov 21 2024 CAZ101-102-221200- /O.CON.KEKA.HW.W.0007.000000T0000Z-241122T1200Z/ Coastal Del Norte-Del Norte Interior- 915 PM PST Thu Nov 21 2024 ...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... * WHAT...South wind gusts up to 60 mph along the coast and up to 75 mph over the interior mountains. * WHERE...Del Norte County. * WHEN...Until 4 AM PST Friday. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain in the lower levels of your home during the windstorm, and avoid windows. Watch for falling debris and tree limbs. Use caution if you must drive. && $$ CAZ103>106-221200- /O.CON.KEKA.HW.W.0007.000000T0000Z-241122T1200Z/ Northern Humboldt Coast-Southwestern Humboldt-Northern Humboldt Interior-Southern Humboldt Interior- Including Shelter Cove, Fortuna, Trinidad, Ferndale, Fernbridge, and Fieldbrook 915 PM PST Thu Nov 21 2024 ...HIGH WIND WARNING REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... * WHAT...South wind gusts up to 60 mph along the coast and up to 75 mph over the interior mountains. * WHERE...Humboldt County. * WHEN...Until 4 AM PST Friday. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain in the lower levels of your home during the windstorm, and avoid windows. Watch for falling debris and tree limbs. Use caution if you must drive. && $$ CAZ109-221200- /O.CON.KEKA.WI.Y.0026.000000T0000Z-241122T1200Z/ Mendocino Coast- Including Fort Bragg, Point Arena, and Rockport 915 PM PST Thu Nov 21 2024 ...WIND ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST FRIDAY... * WHAT...South winds 20 to 30 mph with gusts up to 50 mph. * WHERE...Mendocino Coast. * WHEN...Until 4 AM PST Friday. * IMPACTS...Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. Gusty winds will blow around unsecured objects. Tree limbs could be blown down and a few power outages may result. PRECAUTIONARY/PREPAREDNESS ACTIONS... Winds this strong can make driving difficult, especially for high profile vehicles. Use extra caution. Secure outdoor objects. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka MKK
679 WWUS76 KEKA 221154 NPWEKA URGENT - WEATHER MESSAGE National Weather Service Eureka CA 354 AM PST Fri Nov 22 2024 CAZ101-103-221300- /O.EXP.KEKA.HW.W.0007.000000T0000Z-241122T1200Z/ Coastal Del Norte-Northern Humboldt Coast- 354 AM PST Fri Nov 22 2024 ...HIGH WIND WARNING WILL EXPIRE AT 4 AM PST EARLY THIS MORNING... $$ CAZ109-221300- /O.EXP.KEKA.WI.Y.0026.000000T0000Z-241122T1200Z/ Mendocino Coast- Including Fort Bragg, Point Arena, and Rockport 354 AM PST Fri Nov 22 2024 ...WIND ADVISORY WILL EXPIRE AT 4 AM PST EARLY THIS MORNING... $$ CAZ102-221600- /O.EXT.KEKA.HW.W.0007.000000T0000Z-241122T1600Z/ Del Norte Interior- 354 AM PST Fri Nov 22 2024 ...HIGH WIND WARNING NOW IN EFFECT UNTIL 8 AM PST THIS MORNING... * WHAT...South winds 20 to 30 mph with gusts up to 55 mph. * WHERE...Del Norte Interior. * WHEN...Until 8 AM PST this morning. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain in the lower levels of your home during the windstorm, and avoid windows. Watch for falling debris and tree limbs. Use caution if you must drive. && $$ CAZ104>106-221600- /O.EXT.KEKA.HW.W.0007.000000T0000Z-241122T1600Z/ Southwestern Humboldt-Northern Humboldt Interior-Southern Humboldt Interior- Including Shelter Cove 354 AM PST Fri Nov 22 2024 ...HIGH WIND WARNING NOW IN EFFECT UNTIL 8 AM PST THIS MORNING... * WHAT...South winds 15 to 25 mph with gusts up to 55 mph. Locally up to 66 mph. * WHERE...Humboldt Interior, and Southwestern Humboldt. * WHEN...Until 8 AM PST this morning. * IMPACTS...Damaging winds will blow down trees and power lines. Widespread power outages are expected. Travel will be difficult, especially for high profile vehicles. Wind gusts will be particularly strong along windward ridges and exposed coastal headlands. There is an increased risk of tree branches and other debris on roadways. PRECAUTIONARY/PREPAREDNESS ACTIONS... Remain in the lower levels of your home during the windstorm, and avoid windows. Watch for falling debris and tree limbs. Use caution if you must drive. && $$ For hazard areas see https://www.wrh.noaa.gov/map/?wfo=eka ZVS
What forecasters said that day
The local office's own words before this wind advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Eureka, CA wrote its last area forecast discussion before this wind advisory went out at Nov 20, 5:37 AM PST, 8 hours 46 minutes earlier.
Area forecast discussion, Nov 20, 5:37 AM PST, 8 hours 46 minutes before
AREA FORECAST DISCUSSION
National Weather Service Eureka CA
537 AM PST Wed Nov 20 2024
.SYNOPSIS...A strong atmospheric river storm system will deliver
strong to damaging winds and prolonged moderate to heavy
rainfall, which could lead to life threatening flash flooding,
along with heavy mountain snow. Rain and winds will only briefly
lessen today before ramping up again Thursday when a second
strengthening cyclone brushes our coast, with impacts lasting
through Friday.
&&
.DISCUSSION...Strong southerly winds sweep south with a
progressive boundary this morning, and wind gusts have dropped below
40 mph for most of Humboldt and Del Norte counties as this boundary
has moved SE toward Mendocino, Lake, and Trinity counties. Latest
radar imagery is showing widespread moderate to heavy precipitation
this morning. Most exposed sites in Humboldt and Del Norte saw 45 to
65 mph gusts overnight, and the highest RAWS reports were from:
Kneeland with a gust to 78 mph, Crescent City with a gust to 80 mph,
and Mattole Rd with a gust to 94 mph. Strong gusts of 45 to 55 mph
continue across Mendocino and Lake counties this morning, then this
boundary is forecast to stall over Lake county later today. This
will support wind gusts of around 45 mph at elevations above 1500 ft
in Lake county through the day today, and have extended the wind
advisory.
Latest radar imagery and local precip observations are indicating
widespread moderate to heavy rainfall this morning, with around a
half to an inch and a half of rain having fallen already this
morning in Humboldt and Del Norte. This is a little below what was
expected with this feature, however given the strength of the winds
overnight, precip amounts could be under-reported due to rain
missing the bucket and/or downsloping effects drying out the lower
levels as SE flow moved over the mountains. In any case, lighter
precip rates are expected in the lee of this morning's boundary in
these two counties, while heavier rain rates are forecast to
continue this morning for Mendocino, Lake, and Trinity as it moves
SE.
Guidance continues to hold steady on the general pattern, with with
nearly unanimous agreement depicting an atmospheric river tracking
southward today then stalling over Mendocino this afternoon. A
second cyclone is forecast to take shape and quickly strengthen this
afternoon far offshore as it is drawn in around the parent deep
trough, previously stalled off the Pacific Northwest. The two
surface lows will likely interact with each other complexly, winding
around each other in a Fujiwhara Effect. This places some question
as to how close this strengthening cyclone is to our coast as it
passes northward Thursday, which would have implications to the wind
strength. What is more certain is a reinvigorated atmospheric river
with even higher moisture flux and IVT values. A stream of
persistent, high rainfall rates is forecast to occur in South
Humboldt along Cape Mendocino and through portions of coastal
Mendocino County with this storm Thursday into Friday, with steady
moderate and embedded heavy rainfall elsewhere.
WPC has included our area in a rare High Risk on Thursday through
the described locations, with a wide swath of Moderate risk
elsewhere. An additional 4 to 6 inches with isolated 8 inches is
forecast Wednesday night through Friday, with the bulk falling
Thursday through Thursday Night. This risk category is warranted
with this magnitude of rainfall expected to fall over already
saturated grounds. Meanwhile, mainstem rivers will have continued
upward, with the Eel River at Fernbridge to touch into Moderate
Flood Stage on Friday. Please see the Hydrological Section below for
more details and watch for changes in the river forecasts as models
ingest rainfall verification.
Snow levels out in NE Trinity county have been slow to drop
overnight, however local Caltrans CCTV webcams show snow on highway
299 at Buckhorn (2650 ft) and CHP reports multiple spin-outs on
Highway 36 east of Highway 3 (above 3000 ft). Observations across
the county indicate the freezing level at varying elevations,
however it appears that for the most part they are between 2200 and
3000 ft. Snow levels quickly rise for areas SW of South Fork Mtn.
The heaviest precipitation is a little later than forecast, and just
moving into Trinity County early this morning. Thus heavy snow can be
expected to continue for areas where it is already falling, and snow
levels are expected to rise through the day, first around South Fork
then for areas in NE Trinity. Snow should switch to rain at some
point today for areas below 3000 ft, although when exactly this will
happen remains unclear, and mixed precip within heavier showers is
possible through the day.
After the passage of the secondary cyclone Thursday, most ensemble
guidance shifts the parent trough westward on Friday, which would
put NWRN CA in the cold sector and shut off our subtropical moisture
tap, marking a change from persistent moderate rainfall to showery
rainfall. Rain will likely continue during this period through the
weekend, however be generally less, and with more sparse coverage.
TDJ/JJW
&&
.AVIATION...The strongest winds have diminished at the coastal
terminals while moderate to heavy rain generates periods of MVFR/IFR
visbility's across the area. Winds have kept ceilings fairly high (3-
5K feet) but will likely descend further as rain intensifies. LLWS
is also likely this morning as winds remain elevated aloft while
weakening at the surface. As an occluded front stalls offshore, UKI
will experience similar wind gusts exceeding 30 to 40 mph and heavy
rain through the morning. Widespread, impactful rainfall and gusty
southerly winds 15 to 25 knots will continue through Thursday as
this strong AR makes landfall in northern California. The strongest
LLJ winds will shift south of Cape Mendocino on Thursday and
generate >30 knot gusts across Mendocino and Lake counties.
&&
.MARINE...Seas peaked overnight at around 24 to 26 feet at 13 seconds
with storm force gusts 50 to 65 knots. Winds will continue to
diminish as an occluded front stalls offshore, but seas will remain
steep and hazardous (14 to 16 feet) as a large nearshore NW swell
fills into the waters today. Marginally high surf conditions are
being observed north of Cape Mendocino, but breakers are not
expected to exceed 20 feet with winds largely parallel to the
shoreline. Confidence is increasing for an additional upper
shortwave to produce a fast moving surface low Thursday afternoon
into Friday. Gale force gusts 35 to 40 knots are likely across all
zones as a strong frontal boundary passes through the waters. Brief
but significant southerly wind wave response will help maintain 14
to 16 foot wave heights through the end of the week even as the NW
swell diminishes. Conditions are expected to fall below advisory
levels by this weekend.
&&
.HYDROLOGY...A strong atmospheric river has moved onshore and is
forecast to persist through the rest of this week. NAEFS mean IVT is
showing a prolonged period of anomalously high values (500 to 800
kg/m/s) from the SW, perpendicular to the local terrain. This will
likely lead to a prolonged period of persistent rainfall this week,
further enhanced by the local orography. Latest QPF guidance is
showing 4 to 10 inches of precip falling across the CWA in the next
36 hours, with lighter rain possibly continuing into the weekend.
Latest MRMS soil moisture modeling is indicating 50% to 70%
saturated soils at the moment in Humboldt and Del Norte, with 20% to
30% in Mendocino and Lake Counties. Thus the initial band of precip
today is likely to be mostly absorbed, however with the prolonged
nature of this system, saturation is likely, leading to enhanced
runoff.
Latest ensemble guidance is indicating there may be a second pulse
of intensity Thursday afternoon and Friday, and confidence has
increased on this scenario with the return of some steady heavy and
widespread moderate rainfall. Assuming the first pulse today
saturates soils across the region, this second pulse could lead to
more intense flooding concerns later this week, including main stem
river responses and some life threatening flash flooding. At the
moment the RFC is forecasting the Eel River at Fernbridge to reach
moderate flood stage, and the Russian River at Hopland to reach
Flood Stage on Friday, and the other CNRFC forecast points are
currently forecast to see rapid rises Wednesday and Thursday but
remain below flood stage. Scotts Creek at Lakeport is forecast to
reach 16 feet Thursday and up to 19 feet Friday, and this may have
significant impacts along the creek. TDJ/JJW
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
Flood Watch through Friday evening for CAZ101>106-108>115.
High Wind Warning until 6 AM PST early this morning for
CAZ104.
Winter Storm Warning until 10 PM PST this evening for
CAZ107.
Winter Storm Warning until 6 AM PST early this morning for
CAZ108.
Wind Advisory until 8 AM PST this morning for CAZ109>113.
Wind Advisory until 10 PM PST this evening for CAZ114-115.
NORTHWEST CALIFORNIA COASTAL WATERS...
Hazardous Seas Warning until 9 PM PST this evening for
PZZ450-470-475.
Storm Warning until 7 AM PST this morning for PZZ455.
Hazardous Seas Warning until 9 PM PST this evening for
PZZ455.
&&
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For forecast zone information
see the forecast zone map online:
https://www.weather.gov/images/eka/zonemap.pngIn the hours before
Local storm report, Nov 20, 10:40 AM PST, 3 hours 43 minutes before
Preliminary Local Storm Report
National Weather Service Eureka CA
1040 AM PST Wed Nov 20 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1036 AM Non-Tstm Wnd Dmg 6 NNE Comptche 39.35N 123.56W
11/20/2024 Mendocino CA Law Enforcement
Tree down on Highway 20 blocking the
westbound lane.
&&Local storm report, Nov 20, 11:02 AM PST, 3 hours 21 minutes before
Preliminary Local Storm Report
National Weather Service Eureka CA
1102 AM PST Wed Nov 20 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0948 AM Non-Tstm Wnd Dmg 1 NNW Fort Bragg 39.45N 123.81W
11/20/2024 Mendocino CA Utility Company
1251 customers without power on the
Mendocino coast, including Fort Bragg and
Westport.
&&Local storm report, Nov 20, 11:18 AM PST, 3 hours 5 minutes before
Preliminary Local Storm Report
National Weather Service Eureka CA
1118 AM PST Wed Nov 20 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1117 AM Landslide 11 W Navarro 39.15N 123.73W
11/20/2024 Mendocino CA Law Enforcement
Rockslide reported on Highway 1.
&&Local storm report, Nov 20, 12:00 PM PST, 2 hours 23 minutes before
Preliminary Local Storm Report
National Weather Service Eureka CA
1200 PM PST Wed Nov 20 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1159 AM Landslide 3 ENE Bridgeville 40.48N 123.75W
11/20/2024 Humboldt CA Law Enforcement
Water and rocks reported on Highway 36.
&&Local storm report, Nov 20, 1:49 PM PST, 34 minutes before
Preliminary Local Storm Report
National Weather Service Eureka CA
149 PM PST Wed Nov 20 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0149 PM Landslide 6 SW Gasquet 41.79N 124.06W
11/20/2024 Del Norte CA Law Enforcement
Rocks in the northbound lane of highway 199.
&&Local storm report, Nov 20, 2:22 PM PST, 1 minute before
Preliminary Local Storm Report
National Weather Service Eureka CA
222 PM PST Wed Nov 20 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0150 PM Snow 10 NE Weaverville 40.86N 122.80W
11/20/2024 M13.0 Inch Trinity CA Trained Spotter
13 inches of snow reported as of 1:50 PM.
Snow has transitioned to rain.
&&The office that day
Everything else NWS Eureka, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 20, 2:59 AM PST | Hazardous Seas Warning | EKA | 24 hr | |
| Nov 20, 10:48 AM PST | Areal Flood Advisory | EKA | Lake, Mendocino | 3 hr |
| Nov 20, 1:47 PM PST | River Flood Watch | EKA | Mendocino | 22 hr |
| Nov 20, 2:23 PM PST | High Wind Watch | EKA | Del Norte, Humboldt | 17 hr |
| Nov 20, 3:04 PM PST | Gale Watch | EKA | 12 hr | |
| Nov 20, 3:04 PM PST | Gale Warning | EKA | 42 hr |
Nearby
Wind Advisories in California, 2024Every wind advisory in 2024
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.